GuideUSGS
Earthquake magnitude, intensity and felt reports
Magnitude measures the energy an earthquake released; intensity measures the shaking at a place. Each step of one magnitude is about 32 times more energy. AreaZine has recorded 7,763 U.S. earthquakes of magnitude 2.5 or more from the USGS catalog since April 6, 2026.
By AreaZine · Updated · written with AI tools and checked against the agencies' records (editorial policy)
How often each size happens
| Magnitude | What people notice | U.S. events in AreaZine's record |
|---|---|---|
| 2.5 to 2.9 | often felt near the epicentre, rarely damaging | 4,841 |
| 3.0 to 3.9 | widely felt nearby; objects rattle | 2,539 |
| 4.0 to 4.9 | felt across a region; minor damage possible | 314 |
| 5.0 to 5.9 | can damage weak buildings near the epicentre | 64 |
| 6.0 and over | can cause serious damage over a wide area | 5 |
Source: U.S. Geological Survey earthquake catalog. Data as of record since April 6, 2026.
Why the magnitude changes
The USGS first publishes an automatic solution computed from the nearest seismometers within minutes. A seismologist then reviews it, and the magnitude, location and depth often change by a few tenths. The type of magnitude also matters: local magnitude (ml) and duration magnitude (md) are used for small nearby quakes, moment magnitude (mww, mw) for larger ones. AreaZine reads each event again for seven days and shows the current, reviewed value with its status.
Intensity and "Did You Feel It?"
Intensity describes shaking and damage on the Modified Mercalli scale, written in Roman numerals from I (not felt) to X and above (extreme). The USGS "Did You Feel It?" survey turns people's reports into a community intensity (CDI) for each ZIP code or area; an earthquake page shows how many people reported feeling it and the strongest intensity reported.
Where to look for a quake right now
The USGS latest earthquakes map is the live source. For tsunami information, follow the U.S. Tsunami Warning Centers.